[aequitas]

But a junior can still ask question like: "why isn't there a test for this code", "why are the business logic and algorithm code mixed together" or "why doesn't this align with the design documentation we wrote last week, does it need updating?".

[peterwoerner]

And the junior will learn which things to learn. I certainly think you should allow juniors to code review senior coders work if for nothing more than mentoring, but I am sensitive as to why an overloaded senior would balk at the idea.